In the United States, heart disease is the leading cause of death in postmenopausal women. Estrogen replacement therapy is beneficial for heart disease risk factors as well as for bone density. However, a large proportion of postmenopausal women are not compliant with therapeutic regimens. Phytoestrogens are naturally occurring compounds found in plants and soy products that have estrogenic effects, and may represent an alternative treatment for the prevention of heart disease and osteoporosis in postmenopausal women. However, few intervention trials have examined the extent to which it is possible to improve heart disease risk factors, bone density, and quality of life in postmenopausal women through use of a dietary supplement of Phytoestrogen. The proposed randomized, double-blind, placebo controlled study is designed to determine the acceptability and benefits of use of a dietary supplement of Phytoestrogen (genistein) versus placebo on heart disease risk factors, bone density and psychosocial outcomes in postmenopausal women aged 45-74. Approximately 300 women will be screened in order to enroll 200 (100 treatment, 100 placebo) who will each be followed for one year. Data will be collected at screening and baseline visits, 1 and 3-month follow-up telephone calls, and 6- and 12-month follow-up clinic visits. Measures of HDL, and other heart disease risk factors, hip and spine bone density, and depression, life satisfaction, and quality of well-being will be obtained. Cross-sectional and longitudinal comparisons of treatment and placebo groups will be performed before and after adjustment and stratification for potentially confounding covariates. It is expected that women treated with Phytoestrogen will have higher HDL and bone density, and more favorable psychosocial outcomes. It is also expected that women using Phytoestrogen will have more favorable total cholesterol, LDL, triglycerides, Lp(a), fibrinogen, blood pressure, fasting and postmenopausal challenge glucose and insulin, and fat distribution. Given that women can expect to live one-third of their lives after menopause, the investigators point out that it is important to know how Phytoestrogen may modify heart disease risk factors and bone density. They further state that by defining the influence Phytoestrogen use has, this study would contribute to understanding of how to prevent cardiovascular disease and osteoporosis in postmenopausal women and thereby improve their quality of life.